Andrew Wanogho was shot dead in south-east London in 2006
A man organised a murder from his prison cell using a smuggled mobile phone, the Old Bailey has heard.
Delphon Nicholas is accused of the murder of Andrew Wanoghu, who was shot dead in Brockley, south-east London, in April 2006.
Aftab Jafferjee QC, prosecuting, said "utterly compelling" phone evidence would link Mr Nicholas, who was being held in Belmarsh prison, to his four co-defendants on the murder night.
All five defendants deny murder.
The four others accused are Sereata Barrie, Michael Williams, Trevor Dennie and Erron Cato.
Mr Jafferjee said one of the defendants, Sereata Barrie, had been part of a "honey trap" - her role was to lure Mr Wanoghu to her flat in the early hours of the morning with the promise of sex.
Mr Wanoghu was shot and fatally wounded by a hooded man in the street near her flat at about 0130 BST, he said.
Mr Jafferjee said the dead man had many enemies and had been "set up for execution" by the defendants, who had a variety of grudges against him.
The trial continues.